Lubricating compositions



United States Patent 3,239,462 LUBRICATING COMPOSITIONS Roland F. Bergstrom, Martinez, Calif., and Hyman Ratner, Florissant, Mo., assignors to Shell Oil Company, New York, N.Y., a corporation of Delaware No Drawing. Filed Oct. 15, 1962, Ser. No. 230,756 3 Claims. (Cl. 252-33.6)

This invention relates to improved lubricating oil compositions possessing multifunctional properties. More particularly the invention relates to mineral lubricating oils useful in the lubrication of engines operating over wide temperature ranges and under corrosive extreme pressures and other adverse conditions.

It is known that lubricating oils containing certain metallic salts or soaps such as metal sulfonates possess good dispersing and detergent properties. Such lubricants, however, tend to form metallic deposits in engine parts which interfere with the effective operation of the engine. As a result, recent trends in this field have been to the use of non-ash forming basic and essentially neutral nitrogen-containing dispersants of high molecular weight such' as copolymers of polymerizable amines or amides with long-chain acrylate esters and available commercially under the trade names of LOA-564 or 565, Acryloid 315X, 917 or 966 or certain rather high molecular weight amines, amides and/or imines derivatives of high molecular weight alkenyl maleic anhydride or the like. These non-ash forming nitrogen-containing compounds are excellent detergents but under extreme pressure conditions exhibit a lack of stability and wear inhibiting properties and are non-resistant in combating sludge and corrosion. Attempts to overcome the deficiencies of these polymeric detergent materials either by modifying the polymers or using auxiliary additives has met with little success. In most cases the auxiliary additives which appear to be promising stabilizers and wear inhibitors are metal-containing compounds such as metal sulfonates or metal carboxylates and these are to be avoided for reasons stated. Also these materials tend to complex and form sludge.

It is an object of the present invention to provide an improved lubricating oil composition. It is another ob ject of the invention to provide an improved detergent lubricant possessing good stability and antiwear properties. Still another object of the invention is to provide a corrosion and sludge resistant lubricating oil composition. Other objects will become apparent during the following description of the invention.

Now in accordance with the present invention, it has been found that stability as well as sludge, wear and corrosion inhibiting properties can be imparted to lubricating oils by incorporating therein small amounts of each of certain non-ash forming nitrogen-containing detergents selected from the group consisting of I(A) an oil-soluble amino-imide of a long-chain monosubstituted polymeric hydrocarbyl succinic anhydride and (B) full or partial amino-amides or polyamine salts of long-chain monosubstituted polymeric hydrocarbyl succinic anhydride and (II) an antimony dithiocarmate alone or in combination with an oil-soluble bis-phenol, when the combination (II) is used the antimony dithiocarbate being present in amount of 50-90% of mixture (11). In compounds of (I) by long-chain hydrocarbyl is meant an olefinic polymer straight or branch chain and derived from olefins of from 2 to 8 carbon atoms such as ethylene, propylene, l-butene, isobutene, l-hexene, styrenes and copolymers thereof, from 20 to 500 carbon atoms and a molecular weight of 300 to 5000 preferably from 800 to 1500 as determined by the light scattering method.

It is surprising to find that the antimony dithiocarbamates, alone or in combination with the bis-phenols 3,239,462 Patented Mar. 8, 1966 "ice which will be hereinbelow fully described, and which compounds are known for their anti-oxidant properties should in combination with the non-ash forming polymeric detergents of this invention impart to them properties not exhibited by these compounds when used alone, namely corrosion and wear resistant properties as well as oxidation stability.

The olefinic polymer present as an oil-solubilizing substituent and detergent aid of the nitrogen-containing compounds of the present invention may be prepared by any known means provided it is within the molecular weight range indicated above. Examples of such polymers include polyethylene, polypropylene, polybutene, polyisobutylene, copolymer of ethylene/propylene, copolymer of ethylene/isobutylene, copolymer of ethylene/a-methylstyrene and the like. Monoalkylation of maleic anhydride with the above type olefinic polymers may also be made by conventional means known in the art, preferably in the absence of a catalyst and at temperatures ranging from about 300 F. to 600 F., preferably between 350 F. and 450 F. The mole ratio of the polyolefin to maleic anhydride may vary from 1:1 to 1:10, preferably from 1:1 to 1:5 respectively.

The amines used to form the compounds of (I) (A) namely the succinimides of the compounds or (I) (B), namely the full or partial amides or amine salts of the monosubstituted polymeric hydrocarbyl succinic anhydride can be represented by the formula N[(R NH |(R j -y B1 where the R s can be hydrogen or the same or different C alkyl and/ or aryl radicals and R is an alkylene radical of from 1 to 8, preferably 1 to 4 carbon atoms. Examples of such amines are alkylene polyamines such as ethylene diamine, diethylene triamine, triethylene tetramine, l-methyl ethylene diamine, l-ethyl ethylene diamine, propylene diamine, butylene diamine, trimethyl trimethylene diamine, tetramethylene diamine, diamino pentane or pentamethylene diamine, diaminohexane, hexamethylene diamine, heptamethylene diamine, diamino- Octane, decamethylene diamine, and the higher homologues up to 18 carbon atoms, phenylene diamine, the alkylated phenylene diamines having nuclear substituents such as methyl, ethyl, propyl, butyl, etc, naphthalene diamine, and the alkylated naphthalene diamines;

NHs

eral methods well known to the art. One well accepted method comprises reacting ammonia with an alkyl, or substituted alkyl dihalide. For example, tetraethylenepentamine has been prepared by reacting ammonia with ethylene bromide. The preferred polyamines are the ethylene amines such as ethylene diamine, diethylene triamine,

triethylene tetramine, tetraethylene pentamine, N-dimethyl aminopropylamine, N-dimethylaminobutylamine, N-diethylaminopropylamine methylpropylaminoamylamine.

In forming the second stage of the reaction using the polyamines control of the mole ratio of the monopolyolefinic succinic anhydride and polyamine and the reaction temperature is important to obtaining desired end products of the I(A) or I(B) type. The mole ratio of the polyamine to the anhydride compound can vary from 0.1:1 to 1:1 respectively. The reaction temperature for formation of compounds I(A), the succinimides may vary from 220 F. to 500 F., preferably from 300 F. to 450 F. and in the formation of the compounds I(B) as described above the temperature may vary from room temperature to about 300 F., preferably from 100 F. to 300 F.

The invention is illustrated by the following examples in which the percentages are by weight.

EXAMPLE I.-(TYPE (A) COMPOUND) 250 gms. of polyisobutylene having a molecular weight of 615 and bromine number of 21 was heated to 212 F. and 30 gms. of maleicanhydride was added slowly over a period of 30 minutes. The reactants were heated to 390 F. to 400 F. and maintained at this temperature for four hours and then heated to 440 F. and maintained at this temperature for 16 hours. On cooling, the reactants were dissolved in 1.5 liters of petroleum spirit (60-80" C. RP.) and filtered. 19 gms. of tetraethylene pentamine was added to the petroleum spirit solution. The petroleum spirit was distilled off and replaced by 1 liter of toluene which was also distilled off to azeotropically remove water, and the residue was heated to 390 F. to

400 F. and maintained at this temperature for three hours.

EXAMPLE II A mixture of 1000 gms. (1 mole) of a polybutene havsuccinic anhydride of Example II hereinabove, was

blended with-agitation at 125 F. in a nitrogen atmos-- phere. The temperature was increased to 400 F. during a period of one hour, after; which the absolute pressure. was reduced to about 200mm. Hg during a period of 30- The reaction mixture was then allowed to, reachroom temperature at.

minutes to facilitate the; removaLof water.

this reduced pressure; The reaction product contained 5.1% nitrogen (theory=5.4%). Infra-red analysis showed that the reaction product was an imide. containing a polybuteneside chain.

EXAMPLE III.-(TYPE (A) COMPOUND):

A mixture of 21.3 gms. (0.21 mole) of dimethylaminopropylamine and 150 gms. (0.09 mol) of the polybutenyl succinic anhydride of Example 11 hereinabove, was blended with agitationin a nitrogen atmosphere, and the mixture was heated at 500 F. for a period .of one hour, after which the absolute. pressure was reduced to about 200 mm. .Hg at this temperature during. a period of 30 minutes to facilitate the removal of water and excess amine. room temperature at this reduced pressure. The reaction product, ,contained,l.7% nitrogen '(theory=1.8%).

The identity of :the N-dimethylaminopropylalkenyl suc-v cinimide was established by means of'infra-red spectroscopy. I V

EXAMPLE IVE-(TYPE (B) COMPOUND) to 30 minutes after which the solvent was removed and the end product, a semi-amide of the above reactants, had a nitrogen-content of 1.6%.

Other examples of additives of the present; invention include:

Olefimc-Succinic Anhydride Amine Mole Temp. Type of End Ratio 1*. Product Polyisobutylene (MW 850)sueeinie anhydride Diethylamiue propylamine 1/1 420 (A) Imide. Polyisobutylene (MW 850)-succ1n1c anhydr1de Tetraethylene pentamine. 1. 5/1 120 (B) seimi- 21111 e. Polyethyleuelisobutylene (MW l000)suceinic Dimethylamine propyl- 1/1 450 (A) Imide.

anhydride. amine. Polyethylene/ -methylstyrene (MW 800)-suc- Tetraethylene pentamine--- 1/1 450 Do.

cimc anhydride. Polyisobutylene (MW 1000)sucei.nic anhydride Tetraethylene pentamjne-.- 1/1 120. (B)fAn11i1 1e salt 0 p0 yisosnceinic 1 anhydride.

ing a molecular weight of about 1000 and 98 gms. (1 mole) of maleic anhydride was heated at 410 F. in a nitrogen atmosphere with agitation for a period of 24 hours. The reaction mixture was cooled to 150 F. and 700 cc. of hexane added; after which the mixture was filtered under vacuum. After vacuum distillation to re-.

move the hexane from the filtrate, the product was maintained at 350 F. at an absolute pressure of 10 mm. Hg for one hour to remove traces of maleic anhydride. The crude polybutenyl succinic anhydride thus prepared had a saponification number of 79.

A mixture of 84 gms. (0.45 mol) of tetraethylene pentamine and 702 gms. (0.45 mol) of the polybutenyl The above described non-ash forming detergents such as monopolyalkylene succinimides according'to the invention may be incorporated into lubricating oils in amounts between 0.1% and 10% by Weight, preferably. between 0.25% and 5% by weight, based on the weight of the oil.

The other essential additives are (H9 antimony thiocarbamates such as dithiocarbamatesthe acid portion being represented by the formula:

wherein-the Rs 'are the same or different hydrocarbyl (alkyl, aryl, aralkyl, alkayl, cycloalkyl) radicals having at least'a total of 4 carbon atoms, preferably from .8 to. 18

carbon atoms; total, and Z is selected from the. group con-,-

sisting of sulfur and oxygen, at least one Z being. sulfur.

In case of the. Rs preferred are alkyl radicals which include C -alky1 radicals such'as methyl, ethyl, .propyl,

The reaction mixture was then allowed to reach butyl, octyl radicals or the Rs can be phenyl, naphthyl, benzyl, cyclohexyl radicals and the like. Specific compounds include antimony diethyl dithiocarbamate, antimony dibutyl dithiocarbamate, antimony diamyl dithiocarbamate, antimony dibenzyl dithiocarbamate, antimony diphenyl dithiocarbamate, antimony dicyclohexyldithiocarbamate and the like.

Part of the antimony thiocarbamate, from to 50%, can be replaced with an alkylate bis-phenol having the formula:

wherein X stands for S, SS, Se, SCH -CH ACH -CHR, CR -(CH NH-, O-, and wherein R stands for methyl or ethyl and m stands for an integer from 1 to 3. The preferred al-kylated bis phenols are those having a sulfur bridge or a methylene bridge.

The alkylated bis-phenols may contain from 1 to 8 alkyl groups, but preferably they contain from 2 to 6 alkyl groups. Alkylated bis-phenols having 4 alkyl groups are particularly preferred. Each of the alkyl groups may contain from 1 to 10 carbon atoms, preferably 2 to 6 car-' bon atoms and especially 4 carbon atoms. Furthermore, the alkyl groups contained by any particular bis-phenol maybe the same or different and may also be primary, secondary or tertiary alkyl groups. Bis-phenols containing at least one tertiary alkyl group are particularly preferred.

As examples of the alkylated bis-phenols which may be used according to the invention there are mentioned his 3-ethyl-4-hydroxyphenyl disulfide,

bis(3-methyl4-propyl-5-hydroxyphenyl)disulfide,

bis 2-isopropyl-3-butyl-5-hydroxyphenyl) selenide,

2,2-diethyl-3-tertiary butyl-4",4'-dihydroxy diphenyl selenide,

bis 1,2(2,6'-di-tertiary butyl-4-hydroxyphenyl)thiaethane,

bis 1,2(2,5-di-isopropyl-3-hydroxyphenyl)thiaethane, bis(3,5-di-tertiary butyl-4-hydroxyphenyl)sulfiide, 2,4-di-isobutyl-3-hydroxybenzyl-2',4'-dipropyl-3'-hydroxybenzyl sulfide, bis 1,2(3-octyl-5-tertiary butyl-4-hydroxyphenyl)ethane, bis 1,1 2,6-di-isopropyl-4-hydroxyphenyl ethane, 1,2-bis(2,4-di-tertiary pentyl-3-hydroxyphenyl)propane, bis 2,2(4,5-di-tertiary butyI-Z-hydroxyphenyl) propane, bis(2-tertiary butyl-S-isopentyl-4-hydroxyphenyl)amine, bis(3,5-dibutyl-4-hydroxyphenyl)ether, bis(2,6-dipropyl-4-hydroxyphenyl)ether.

Examples of alkylated bis-phenols having a sulfur bridge are bis(2,5-dipentyl-4-hydroxyphenyl)sulfide, bis(2,5-diheXyl-3-hydroxyphenyl)sulfide, bis(2-methyl-5-tertiary butyl-4-hydroxyphenyl)sulfide, bis(2-methyl-5-tertiary butyl-6-hydroxyphenyl)sulfide and particularly bis(3-tertiary butyl-5-methyl-2-hydroxyphenyl sulfide.

Examples of alkylated bis-phenols having a methylene bridge are bis(2,3-di-tertiary butyl-4-hydroxyphenyl)methane, bis 2,5 -di-terti ary butyl-4-hydroxyphenyl methane, bis(2,6-di-tertiary butyl-4-hydroxyphenyl)methane, bis 3,5 -di-tertiary octyl-4-hydroxyphenyl methane, bis 3-tertiary butyl-5-tertiary octyl-4-hydroxyphenyl) methane, and especially bis(3,5-di-tertiary butyl-4-hydroxyphenyl)methane.

The alkylated bis-phenol may be prepared by any of the methods known in the art of bis-phenol manufacture, for example, by selecting the appropriate alkylated phenols as starting materials and condensing them together by any of the established methods.

Each of the above discussed additives can be used as oil additives in amounts ranging from about 0.05% to about 10%, preferably from about 0.1% to about 5% by weight.

Lubricating oils which can be used as base oils for the lubricating oil compositions according to the invention include a wide variety of lubricating oils, such as naphthenic base, paraffin base, and mixed base lubricating oils, other hydrocarbon lubricants, e.g., lubricating oils derived from coal products, and synthetic oils, e.g., alkylene polymers (such as polymers of propylene, butylene, etc., and the mixtures thereof), alkylene oxide-type polymers (e.g., alkylene oxide polymers prepared by polymerizing the alkylene oxide, e.g., propylene oxide, etc., in the presence of Water or alcohols, e. g., ethyl alcohol), dicarboxylic acid esters (e.g., those which are prepared by esterifying such dicarboxylic acids as adipich acid, azel-aic acid, suberic acid, sebasic acid, succinic acid, fumaric acid, maleic acid, etc., with alcohols, such as butyl alcohol, hexyl alcohol, Z-ethylhexyl alcohol, dodecyl alcohol, etc.), liquid esters of acids of phosphorus, alkyl biphenyl ethers, polymers of silicon (e.g., tetraethyl silicate, tetra-isopropyl silicates, tetra (4-methyl-2-tetraethyl) silicate, hexyl (.4-methyl-2- pentoxy) disoloxane, poly(methyl) siloxane, and poly- (methylphenyl)siloxane.

The above base oils may be used individually or in combinations thereof, wherever miscible or wherever made so by the use of mutual solvents.

The following lubricating compositions are representative of the invention.

Composition A: Percentage Example I additive 4 Antimony diamyl dithiocarbamate 0.5 Mineral lubricating oil (SAE 20) Balance Composition B:

Example II additive 4 Antimony diamyl dithiocarbamate 0.5 Bis(3,5-ditert-butyl-4-hydroxyphenyl)methane 0.3 Mineral lubricating oil (SAE 20) Balance Composition C:

Example III additive 2 Antimony dibutyl dithiocarbamate 0.5 Bis(3,5-ditert-butyl-4-hydroxyphenyl)methane 0.3 Mineral lubricating oil (SAE 20) Balance Composition D:

Example IV additive 5 Antimony dibenzyldithiocarbamate 0.5 Bis(3,5-ditert-butyl-4-hydroxyphenyl)methane 0.2 Mineral lubricating oil (SAE 20W-30) Balance Composition E:

Example I additive 4 Bis(3,5-ditert-butyl-4-hydroxyphenyl)methane 0.2 Antimony diamyl dithiocarbamate 0.5 Mineral lubricating oil Balance Composition F:

Example I additive 1.5 Antimony diamyl dithiocarbamate 0.25 Phenyl-a-naphthylamine 0.07 Mineral lubricating oil (SAE 20) Balance Compositions of the present invention are tested under various test conditions and gave excellent results as shown below:

7 8i Test results [B asc: Mineral lubricating oil] TESTS 1r III Compositions 1 Cu-Pb Percent Pent. "1v

Wt. Loss Incr. in Isol. Hrs. r Lacquer Total mg. Vis. at Percent Composition B 46. 7 1- 3 3. 5 0. 03' Composition C 33. 7 3. 3 1. 9 0. 03 Composition A Composition A CompositionF Y X=Minera1 Oil (SAE )+4% Ex. II Po1ymer 3. 5 g 301 144 1. 76 Y=M1neral Oil (SAE 20)+4% Ex. II Polymer"..- t Y=Minoral Oil (SAE 20)+0,5% zinc dianlyl dithiocarbamate 22. 4 160-300 Z=Mineral Oil (SAE 20)+5% Ex. II Polymer +05% bis (3,5-ditert-butyl-L-hydroxyphenyDmethane 20.6 487 100 0. 63 73-360 XX=Mineral Oil (SAE 20) +13% copolymer of vinyl-- pyrrolidone/lauryl methacrylate+1% bis (3, 418 (A) 4 117 r fi-dltert-butyl-4-hydr0xypheny1)methane 120 (B) 61.8 174 Also Composition A was tested in the Caterpillar gas antimony dialkyl dithiocarbamate the alkyl radicals totalengine test for 240 hours and the results were asfollows: 1y having 4-1-8 carbon atoms. t Piston ring land lacquer demerits 47.9 lrubrwatmgfollf 'l i g F essentflany Piston ring groove lacquer demerits 5 0 a 1 amoun 0 mmera l'lcatlng 01 and Tom Piston ring lacquer demerits 102 b t 0 5% to ab0ut 10,% by weight of eachiof (I) an oil-soluble aliphatic amino-imide of :monopolyisobutylene Above total demerits 1 3 substituted succinic anhydride' the polyisobutylene radical 1 Basis 1000 possible demerits. v

for example acidless tallow, oleic acid amines SuchLas phenyl-ot-naphthylamine, N,N'-disecbutyl' diamino phenyl oxide, octadecylamine and the like.

We claim as our invention:

1. A lubricating composition consisting essentially of a major amount of lubricating oil and from about 0.5% to about 10% by weight of each of (I-) an oil-soluble aminoimide of a mono C polyolefin substituted succinic anhydride the amine used to form the amino-imidesbeing a polyalkylene polyamine and (II) an oil-soluble having a molecular weight of from 500m 3000 and theamine used to form the .aminoamide' being tetraethylene- V pentamine and (II) antimony diamyl dithiocarba'mate.-

3. A lubricating oil composition consisting essentially;

of a major amount of mineral lubricating oil and from about 0.5% to about 10% by weight of each of (I); an oil- I soluble aliphatic amino-imide of monopolyisobutylene substituted succinic anhydridet the :polyisobutylenemadical having a molecular weight of from 500 to 3000 and the, amine used" to form the aminoarnidebeing dimethyl' aminopropylamine and. (II) antimony diamyldi- DANIEL E. WY MAN, Primary Examiner. 

1. A LUBRICATING COMPOSITION CONSISTING ESSENTIALLY OF A MAJOR AMOUNT OF LUBRICATING OIL AND FROM ABOUT 0.5% TO ABOUT 10% BY WEIGHT OF EACH OF (1) AND OIL-SOLUBLE AMINOIMIDE OF A MONO C20-300 POLYOLEFIN SUBSTITUTED SUCCINIC ANHYDRIDE THE AMINE USED TO FORM THE AMINO-IMIDES BEING A POLYALKYLENE POLYAMINE AND (11) AN OIL-SOLUBLE ANTIMONY DIALKYL DITHIOCARBAMATE THE ALKYL RADICALS TOTALLY HAVING 4-18 CARBON ATOMS. 